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  • Hobart Bar Aid turning off randomly

     fixbear updated 2 weeks, 6 days ago 4 Members · 17 Posts
  • okwestern

    Member
    September 1, 2020 at 12:09 pm

    Our Bar Aid turns off randomly. Not sure where to start with this problem. PCB looks flawless without any corrosion/water damage.

    It also overfilled from time to time so today I replaced the pressure transmitter. I guessed that both would not fail at the same time so I first tried the right. Did not help, so i replaced the left. Not sure if this causes the machine to turn off (fill timeout)?

  • fixbear

    Member
    September 1, 2020 at 7:50 pm

    Bar aids are not sold here in the states, But what model is it?

  • okwestern

    Member
    September 1, 2020 at 7:55 pm

    Seems like a Baraid 500 (but I’m with the machine at the moment, so I’m not sure). See PCB and front panel.

  • fixbear

    Member
    September 2, 2020 at 6:35 am

    Being I’ve never worked on one, but understand their principle operation, Have you checked the temp sensors. A lot of glassware cleaners have to have sanitizing temps to operate and will pause to wait for heat. You may have a heating element out.

  • fixbear

    Member
    September 2, 2020 at 7:05 am

    okwestern, I forgot to mention water pressure sensor. Like a common line and someone turns on a tap will trip it.

  • okwestern

    Member
    September 2, 2020 at 7:15 pm

    I’ll measure the sensors and elements. I guess the sensors are 10k or 100k NTC? Or K-type?

  • okwestern

    Member
    November 3, 2020 at 1:51 pm

    Appears the temp sensors are 10k NTC (pn: 775612-1). I immersed both in ice water (measured to 1’C degree) and boiling water. (10k NTC should read 26k at 1’C and 0.97k at 100’C). I measured both and they was almost exactly the same, 33-35k (-4 to -6’C) at 1’C and 1k at 100’C. My brand new 10k NTC read exactly 26k. Seems odd, both should fail at the same time. But would 5 to 6 degrees offset cause the machine to intermittently turn off? I would expect this if the value was way off, but not by 5-6 degrees? And since the machine operates around 60-80’C (not 1’C), the offset is much smaller, if any. I only had one new sensor so I replaced the sensor at the small closed tank at the bottom (not the open “bowl” like heater inside the machine). No improvement. I also double checked the detergent, rinse aid and water hardness settings.

    I’m getting crazy with this machine.

    Any tips?

  • fixbear

    Member
    November 3, 2020 at 3:15 pm

    Does it have adequate water pressure through the whole cycle?

  • okwestern

    Member
    November 3, 2020 at 3:26 pm

    It hasn’t turned off during a cycle so far, just between cycles, when it’s not in use (we only wash cutlery and plasticware in it, so it’s not in constant use). I suspected it entered a standby mode or similar after some time. But I can’t find anything about it in the manual. It’s been operating fine since it was new in 2015, and we have the same equipment on the same water line as always.

    I measured the 3 elements on the closed water tank, and the 1 element in the inside open bowl, all read fine, 45-60 ohms, no short to ground.

  • beef

    Member
    November 4, 2020 at 7:46 am

    Got a schematic, I’m thinking high limit on the heaters, possible relay sticking? 🧐

  • okwestern

    Member
    November 4, 2020 at 7:50 am

    Nice. Would you send it to me?

  • Bradley Hannah

    Member
    November 4, 2020 at 11:06 pm

    Hobart dishwashers are also susceptible to failure in the door switches/sensor causing the relay board to turn itself off, thus dropping the power out of the main display. What do you do to get the unit to turn back on? Do you unplug it, plug it back in and reboot it, just turn it back on at the right hand side i/O button or does it come back on by itself?

    When you open the door, does the display go out as well? This might help you mimic the fault you are getting.

  • Bradley Hannah

    Member
    November 4, 2020 at 11:09 pm

    One other thing you need to think about is the ribbon cable that connects to the display board from the main PCB. There may be a fault with that cable or connection that is causing the washer display to come on and off like it is.

  • okwestern

    Member
    November 5, 2020 at 6:38 am

    I must manually turn it on with the right hand side i/O button. I doubt it’s the display cable, as it’s completely turned off (i hear the relays clicking when I turn it on again). Opening/closing the door doesn’t do anything (as far as I’ve seen, though I haven’t looked for any behaviour when using the door).

    Could a failing contactor be the problem? The machine only turns off now and then, I’m not sure if a contactor would just fail now and then, or completely break down…. I just want to ask before replacing it.

  • Bradley Hannah

    Member
    November 5, 2020 at 7:54 pm

    How many staff use the machine? Does a right handed person use it? Does the door have a indented latch point which possibly they are using their thumb on the control panel to leverage the door open. Maybe the thumb bumps the I/O button, haha.

    Is there steam leakage coming up into the panel causing a failure of the board or a circuitry short. There maybe a small capacitor on the PCB that has received some steam damage and is not holding charge causing it to drop out.

  • okwestern

    Member
    November 6, 2020 at 5:47 am

    I’m pretty sure it’s not user error, since it happened while I was working on it. I turned my back to the machine to read the parts diagram. Then after a few minutes, it was turned off.

    It seems to have some steam leakage coming out from the top part of the door, but I’m not sure how much is “normal” for these machines. PCB seems to be without corrotion/water/steam damage (i’m electrical engineer so I can usually spot this quickly). Of course the electrolytic capacitor might be damaged, I could try to replace it.

  • fixbear

    Member
    November 6, 2020 at 9:19 am

    It sounds more and more like a loose or corroded electrical connection. Sensor, comm, or hold in contacts of a relay. The worse kind to find with any certainty.. The kind that keeps you awake at night. Good luck.

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